The present invention pertains to an air intake stack which is to be used in combination with an agricultural combine of the type employing a rotary screen air cleaner to filter air which is subsequently used to cool the internal combustion engine, hydraulic system and cab air conditioning system of the combine. Specifically, the air intake anti-fouling stack provides an elevated air intake port which is less susceptible to collecting debris-filled air.
Self-propelled agricultural combines are driven by internal combustion engines. The engine is placed in an engine housing which isolates the engine and hydraulic system from exposure to the ambient air, which frequently contains dust and chaff from the crop being harvested.
When a combine is in use, it is driven through a field of mature grain. The grain is cut by a rotary cutter on the front of the combine and then fed into the innards of the combine. Inside the combine, the grain is separated from the stocks and chaff, and is stored on board the combine, or, discharged through a grain elevator to a collecting bin, usually mounted on a truck chassis, which moves along side the combine. The chaff from the grain is ejected through a residue discharge port in the rear of the combine.
Frequently, several combines and their support vehicles operate in one field at the same time. The result is that, while the grain is rapidly harvested, the concentration of harvest debris, i.e., straw, chaff and dust, is quite high. Particularly in the case where several combines are operating, usually in a "V" or singlewing formation, the trailing units are surrounded by debris stirred up by the leading units.
Two sources of relatively clean air must be supplied to the combine. The first source must be totally free of debris and dust as it is used to mix with the fuel and provide power to the combine through its internal combustion engine. A combustion air intake fulfills this purpose and is usually of the truck-type water-filled air cleaner. It is mounted behind and above the cab, in an area where the air contains less debris than would be found closer to the ground.
The second air supply provides cooling for the engine, the hydraulic system and the cab air conditioning. The rotary screen air filter is a device which cleans cooling air and has been in use on agricultural combines for some time. The screen is generally formed as a closed cylinder, like a cake, and mounted vertically on the side of the combine. Enclosed within the screen or within the engine housing adjacent the screen is an impeller blade or fan which is driven off the airflow caused by an engine-driven cooling fan. A wedge-shaped portion of the screen is internally baffled to prevent airflow through the screen at that particular portion, which is generally located at the bottom of the screen. In operation, the engine driven fan draws air through the screen in all unbaffled portions. Dust and chaff collect on the screen over most of its surface, and drop off of the screen when the portion of the screen to which it is adhering rotates adjacent the internal baffle. The effects of gravity and the lack of lower internal pressure at the location of the baffle combine to allow any particulate matter to drop off of the screen.
While the rotary screen is a definite improvement over a static air filter device, in operation, chaff and dust particles frequently stick to the screen with sufficient adhesion to prevent the forces of gravity from removing the particles once a lower pressure area internal the screen is effected. If the screen becomes sufficiently clogged, airflow into the engine compartment is restricted, the engine and hydraulic system will begin to overheat, potentially damaging the mechanical structures which must be kept cool. The combine operator must stop the combine and manually clean the screen to prevent damage to the combine. The operator must also raise the engine compartment hood and blow chaff and dirt, which has passed through the rotary screen, from the engine radiator and from the hydraulic and air conditioning cooling coils. These stops are both costly and inefficient and can largely be eliminated through the use of the device proposed in this application.
The instant device is an anti-fouling air intake stack which completely surrounds the rotary screen air intake and draws air through the top of the stack, which is located four to five feet above the rotary screen. By drawing air into the combine engine through this anti-fouling stack, the combine operator is relieved of the frequent manual task of cleaning the rotary screen.
The primary object of the invention then, is to raise the location of the cooling air intake on an agricultural combine to a height above the ground that does not contain as much foreign particulate matter as would a lower elevation.
A secondary object of the invention is to provide an air intake which will allow a combine operator to operate the combine for longer periods of time between having to manually clean a rotary screen air intake or the cooling radiator and coils within the engine compartment.
These and other advantages and objectives of the present invention will become more fully apparent as the description which follows is read in conjunction with the accompanying drawings.